No the modules cannot be in the U-Boot env. What I suspect though is that the env was specifying another uImage file, different from yours, which tries to load the OV8820 camera.

Are you sure it was your kernel booted up when the camera issue appeared? If you check the first line of the dmesg output you'll see when it has been built and on which machine. Is there only one sdcard plugged into the board? No SATA nor USB drive?